Border of the island of inversion: Unbound states in Ne 29

M. Holl, S. Lindberg, A. Heinz, Y. Kondo, T. Nakamura, J. A. Tostevin, T. Nilsson, N. L. Achouri, H. Al Falou, L. Atar, T. Aumann, H. Baba, K. Boretzky, C. Caesar, D. Calvet, H. Chae, N. Chiga, A. Corsi, H. L. Crawford, F. DelaunayA. Delbart, Q. Deshayes, P. Díaz Fernández, Z. Dombrádi, C. A. Douma, Z. Elekes, P. Fallon, I. Gašparić, J. M. Gheller, J. Gibelin, A. Gillibert, M. N. Harakeh, A. Hirayama, A. Horvat, Horváth, T. Isobe, J. Kahlbow, N. Kalantar-Nayestanaki, S. Kawase, K. Kisamori, T. Kobayashi, D. Körper, S. Koyama, I. Kuti, V. Lapoux, F. M. Marqués, S. Masuoka, J. Mayer, K. Miki, T. Murakami, M. Najafi, K. Nakano, N. Nakatsuka, A. Obertelli, F. De Oliveira Santos, N. A. Orr, H. Otsu, T. Ozaki, V. Panin, S. Paschalis, A. Revel, D. Rossi, A. T. Saito, T. Y. Saito, M. Sasano, H. Sato, Y. Satou, H. Scheit, F. Schindler, P. Schrock, M. Shikata, Y. Shimizu, H. Simon, D. Sohler, O. Sorlin, L. Stuhl, S. Takeuchi, M. Tanaka, M. Thoennessen, H. Törnqvist, Y. Togano, T. Tomai, J. Tscheuschner, J. Tsubota, T. Uesaka, M. Yasuda, K. Yoneda

Research output: Contribution to journalArticlepeer-review


The nucleus Ne29 is situated at the border of the island of inversion. Despite significant efforts, no bound low-lying intruder f7/2 state, which would place Ne29 firmly inside the island of inversion, has yet been observed. Here, the first investigation of unbound states of Ne29 is reported. The states were populated in Ne30(p,pn) and Na30(p,2p) reactions at a beam energy of around 230 MeV/nucleon, and analyzed in terms of their resonance properties, partial cross sections, and momentum distributions. The momentum distributions are compared to calculations using the eikonal, direct reaction model, allowing ℓ assignments for the observed states. The lowest-lying resonance at an excitation energy of 1.48(4) MeV shows clear signs of a significant ℓ=3 component, giving first evidence for f7/2 single particle strength in Ne29. The excitation energies and strengths of the observed states are compared to shell-model calculations using the sdpf-u-mix interaction.

Original languageEnglish
Article number034301
Number of pages11
JournalPhysical Review C
Issue number3
Publication statusPublished - 1 Mar 2022

Bibliographical note

Funding Information:
We thank Alfredo Poves and Frédéric Nowacki for providing results from large-scale shell model calculations. Support was provided by the Swedish Research Council under Grant Nos. 2011-5324 and 2017-03839. This work was supported partially by JSPS KAKENHI Grant Nos. JP16H02179 and JP18H05404. J.A.T. acknowledges visiting researcher support at Tokyo Institute of Technology from MEXT KAKANHI Grant No. JP18H05400 and the support of the Science and Technology Facilities Council (U.K.) Grant No. ST/L005743/1. The LPC-Caen group wished to acknowledge support from the Franco-Japanese LIA-International Associated Laboratory for Nuclear Structure Problems as well as the French ANR-14-CE33-0022-02 EXPAND. This project was partly funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project-ID 279384907 - SFB 1245 and the GSI-TU Darmstadt cooperation agreement. This work was in part supported by the Institute for Basic Science (IBS-R031-D1) in Republic of Korea. Additional support from the European Regional Development Fund Contract No. GINOP-2.3.3-15-2016-00034 and the National Research, Development and Innovation Fund of Hungary via Project No. K128947. I.G. has been supported by the Helmholtz International Center for FAIR and the Croatian Science Foundation (Hrvatska Zaklada za Znanost) under projects no. 1257 and 7194. Y.T. acknowledges the support by JSPS Grant-Aid for Scientific Research Grants No. JP21H01114. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357 (ANL).

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